package com.example.yls.demoa;

import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity
         implements IOnUpdateListener{
        private TextView txtTime;
        private MyReceiver receiver;

        @Override
        protected void onCreate(Bundle savedInstanceState){
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            receiver = new MyReceiver(MainActivity.this);
            IntentFilter filter = new IntentFilter();
            filter.addAction(Intent.ACTION_TIME_CHANGED);
            filter.addAction(Intent.ACTION_TIME_TICK);
            filter.addAction(Intent.ACTION_TIMEZONE_CHANGED);
            registerReceiver(receiver,filter);

            txtTime = findViewById(R.id.txt_time);
            updateTime();
        }

        @Override
        public void updateTime(){
            Calendar calendar = Calendar.getInstance();
            int hour = calendar.get(Calendar.HOUR);
            int min = calendar.get(Calendar.MINUTE);
            //时间加0,两位数
            StringBuffer buffer = new StringBuffer();
            if(hour <10){
                buffer.append("0");
            }

            buffer.append(hour);
            buffer.append(":");

            if(min<10){
                buffer.append("0");
            }

            buffer.append(min);

            txtTime.setText(hour + ":" + min);
        }

        @Override
        protected void onDestroy(){
            unregisterReceiver(receiver);
            super.onDestroy();
        }
}


















